1. Technical Field of the Invention
The present invention relates to a switch device, and more particularly to a switch device used for opening or closing a window in an automobile-installed power window device.
2. Prior Art
With reference to the drawings, a description will be made of a conventional switch device.
FIG. 9 is an exploded perspective view showing a conventional switch device; FIG. 10 is a perspective view showing a conventional knob of the switch device; FIG. 11 is a sectional view taken on line 11--11 in FIG. 10; and FIG. 12 is s sectional view showing a conventional panel, a knob and a housing in the switch device.
As shown in FIGS. 9 to 12, the conventional switch device is schematically constructed of a panel 1; a plurality of (for example, two) knobs 20 to be housed in the panel 1; a housing 3 with which the panel 1 is engaged; a switch unit 4 which is housed in the housing 3 and to which the knobs 20 are mounted; a printed circuit board 5 to which the switchunit 4 is connected; and a cover 6 for housing the printed circuit board 5.
The panel 1 is made of synthetic resin material, is formed by fabrication, and has a substantially plane panel unit 1a; a side wall 1b which is orthogonal to the panel unit 1a from the back surface thereof and substantially surrounds the periphery of the panel unit 1a; and a plurality of (for example, two) concave portions 1c, each shaped to have a bottom, provided in a substantially central portion of the panel unit 1a. Also, the concave portion 1c has a pair of mutually opposed inclined walls 1d, a curved surface wall 1e provided between the pair of inclined walls 1d, and a substantially rectangular hole if. The bottom of the concave portion 1c is constituted by the curved surface wall 1e, and part of this bottom is provided with the hole if.
The pair of inclined walls 1d are inclined such that an interval therebetween becomes narrower away from the panel unit 1a. Also, this concave portion 1c on a side of the plane of the panel unit 1a of the panel 1 is open.
The knob 20 has a substantially box-like shape, made of synthetic resin material, formed by fabrication, and has a curved surface-shaped top surface wall 20a; a pair of first side walls 20b substantially orthogonal to the top surface wall 20a; a second side wall 20c provided between the pair of first side walls 20b, substantially orthogonal to the first side walls 20b; and an opening 20d on a side opposite to the top surface wall 20a. The periphery of the top surface wall 20a is subjected to so-called chamfering, and is formed into a curved surface shape. One end portion of the top surface wall 20a in the longitudinal direction protrudes outwardly to be formed as an operating unit 20g, while the other end portion extends to the opening 20d.
One surface (outer side) of the pair of first side walls 20b is inclined such that the interval becomes wider from the top surface wall 20a side toward the opening 20d, and the other surface (inside side) is provided to be substantially orthogonal to the top surface wall 20a. More specifically, the first side walls 20b are formed such that the thickness dimension thereof becomes thicker from the top surface wall 20a side toward the opening 20d for manufacturing reasons to be described later. A circular hole 20f is formed on the first side wall 20b.
In other words, this knob 20 is formed such that a width dimension to be formed between the pair of first side walls 20b becomes gradually larger from substantially the top surface wall 20a (socalled apex of knob 20) toward the opening 20d. Also, the knob 20 constitutes a so-called finger grip portion.
A housing 3 is made of synthetic resin material, is formed by fabrication, and has a substantially rectangular top wall 3a; a side wall 3b extending outwardly from the top wall 3a and surrounding the periphery; and a plurality of (for example, two) mounting units 3c provided at a substantially central portion of the top wall 3a.
The side wall 3b is provided with a plurality of (for example, six) rectangular convex portions 3e and a rectangular hole 3f.
The mounting unit 3c has a rectangular hole 3d, wall portions 3g provided all around the hole 3d, and a pair of cylindrical column-shaped convex portions 3h provided to oppose to the mutually-opposed wall portions 3g. This housing 3 is housed into the panel 1 from the side of the opened plane of the panel 1, and is arranged by appropriate means such as snap-in. At this time, the mounting unit 3c of the housing 3 is housed and arranged within the concave portion 1c of the panel 1.
The knob 20 is inserted into the concave portion 1c, and the pair of convex portions 3h of the mounting unit 3c are inserted into the circular hole 20f in the first side wall 20b of the knob 20, whereby the knob 20 is arranged to enable it to rock with respect to the housing 3.
In this state, the pair of inclined walls 1d of the concave portion 1c in the panel 1 and the pair of first side walls 20b of the knob 20 are assembled to oppose to each other so as to have different directions of inclination. Therefore, a gap dimension 12 (See FIG. 12) between the inclined wall 1d and the first side wall 20b on the panel unit 1a side is set to a comparatively large value, and a gap dimension 13 of the concave portion 1c on the bottom side is set to a comparatively small value (12&gt;13).
That is, the gap dimension between the inclined wall 1d and the first side wall 20b is set so as to become gradually larger from the bottom side of the concave portion 1c toward the panel unit 1a side.
Next, a description will be made of a forming mold for manufacturing a conventional knob for the switch device. FIG. 13 is a sectional view showing a forming mold for manufacturing the knob for the switch device. As shown in FIG. 13, this forming mold is schematically constructed of: a first mold 41 as a stationary mold; a second mold 42 to be inserted into the first mold 41, as a movable mold; and a third mold 43, as a slide core, to be mounted to the first mold 41, and to be slid so as to sandwich the second mold 42 therebetween.
The first mold 41 has a concave portion 41a which is substantially U-shaped in cross section, and whose angular portions have been chamfered. In this concave portion 41a, mutually-opposed sides in the concave portion 41a are inclined such that they are slightly opened toward an open end side. The mutually-opposed inclined sides within the concave portion 41a are provided in order to reliably and easily release on releasing a knob to be fabricated by this forming mold from the forming mold.
The second mold 42 is shaped like an inverted, substantially T-character in cross section, and has a base 42a and a convex portion 42b protruding outward (upward) from the substantially central portion of one surface (upper surface) of the base 42a. The structure is arranged such that the tip end portion of the convex portion 42b is arranged to oppose within the concave portion 41a of the first mold 41 and that the convex portion 42b goes in and out of the concave portion 41a. When the end surface of the first mold 41 has abutted upon the base 42a of the second mold 42, substantially U-shaped space is formed between the concave portion 41a and the convex portion 42b.
A third mold 43 is substantially T-shaped in cross section, and has a pair of bases 43a, which slide, and a pair of cylindrical column-shaped convex portions 43b, each protruding outward from one side of the base 43a. The tip end portion of the convex portion 43b abuts upon the side of the convex portion 42b of the second mold 42, and the convex portion 43b is used to form the circular hole 20f in the first side wall 20b.
More specifically, this third mold 43 slides as if it sandwiched the second mold 42, and slides until the cylindrical column-shaped convex portion 43b abuts upon the second mold 42.
A parting line (PL) of the knob 20 obtained by fabricating using a forming mold having a structure described above is provided near the opening 20d in the first side wall 20b.
Next, a description will be made of a forming mold for fabricating the panel 1 in the switch device although not shown. The pair of inclined walls id for constituting the concave portion 1c in the panel 1 are formed using a forming mold having an inclined surface, and the inclined surface of the mold is required to reliably and easily release from the mold on releasing a panel 1 to be obtained by fabrication, from the forming mold.
In the conventional switch device, however, the pair of inclined walls 1d in the concave portion 1c of the panel 1 and the pair of first side walls 20b of the knob 20 are arranged to oppose to each other, and the respective angles of inclination become different in direction when assembled, and the gap dimension therebetween becomes a comparatively large dimension.
Consequently, a gap dimension 12 with the top surface wall 20a of the knob 20 on the side of the panel unit 1a of the panel 1 becomes large, and therefore, there is the problem that when foreign matter such as dust enters this gap, the operability of the knob 20 will be deteriorated.
Also, when the gap dimension is comparatively large, there is the problem that this gap becomes undesirable also in view of a fine appearance.